The same people will say Flash was slow by default. I remember running canvas vs flash rendering tests in mobile Safari when the plugin was still available, and Flash blew canvas rendering away. Of course it was all about what you chose to do with it... no one was writing really complicated behaviors in canvas at that point, and wasm didn't exist, so if you wanted special animation or complexity you used Flash. The appropriate thing would have been to have Flash off by default until someone tapped an embed to load it.